Implant devices are devices that are adapted for being placed in e.g. human bodies or animals, and that e.g. replace body parts that have been damaged or removed e.g. due to cancer.
In order to keep the implant device in place so that it does not move freely within e.g. a human body cavity, it is known to fasten the implant device in position using a fastening device. A known fastening device is a band type device having two ends, where a first end has a hole, and a second end has a protruding part arranged to be placed in said hole in order to lock the two ends of the band type device together after having been looped around an implant device and a body part such as an intestine, thereby fastening the implant device in place. In order for the band ends not to be separated when e.g. a person carrying the implant moves around, the protruding part is of flexible material and has a ball shaped outer end of somewhat larger cross-section than the diameter of the hole, whereby the ball shaped end is elastically deformed when pushed through the hole and regains its shape when leaving the hole, thus keeping the band ends locked to each other.